Verdict · NHTSA data
Limited data — recalls on file
NHTSA has just 0 complaints on file for the 1979 Mack R Series — too few to judge reliability from owner reports alone — but 5 recall campaigns apply to this year, so any used example should have its VIN checked for completed recall work.
0
NHTSA complaints
5
Recalls
0
Investigations
0
Crash-involved
0
Fires reported
0
Injuries
0
Deaths
—
NCAP overall
5 NHTSA recall campaigns on file. Recall repairs are free at franchised dealers.
Defect
SPRING SEAT CAN DEFORM, WHICH CAUSES A DECREASE IN THE CLAMPING FORCE IN THE SUSPENSION ASSEMBLY. LOSS OF CLAMPING FORCE MAY BRING ABOUT AXLE MISALIGNMENT OR AXLE HOUSING FAILURE.
Remedy
THE AXLE HOUSING WILL BE INSPECTED AND REPLACED, IF NECESSARY. THE SPRING SEATS WILL ALSO BE REPLACED.
Defect
THE RIGHT HAND CLEARANCE LAMP IS OBSCURED, FROM CERTAIN ANGLES OF VISION, BY THE IN-LINE PRECLEANER AIR CLEANER CAP. THE INVOLVED VEHICLES FAIL TO CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, "LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT".
Remedy
DEALER WILL REPLACE THE AIR CLEANER WITH ONE OF ACCEPTABLE HEIGHT.
Defect
THE RETAINING PIN FOR THE BRAKE CONTROL KNOB HAS BEEN MISALIGNED (OFF THE CENTER LINE OF THE VALVE PLUNGER HOLE). THIS CAUSES THE KNOB TO BE OVERSTRESSED AT THE RETAINING PIN HOLE AREA CAUSING IT TO SEPARATE FROM THE VALVE.
Remedy
THE HOLES WILL BE RETOOLED TO PROVIDE CORRECT ALIGNMENT AND PLASTIC KNOBS WILL BE REPLACED BY KNOBS OF STRONGER MATERIAL HAVING METAL REINFORCEMENTS.
Defect
ON CERTAIN VEHICLES, THE KNOB THAT OPERATES THE TRACTOR PARK VALVE MAY BREAK OFF, RENDERING THE VALVE INOPERABLE.
Remedy
DEFECTIVE KNOBS WILL BE REPLACED WITH AN IMPROVED TYPE, WITHOUT CHARGE TO OWNER.
Defect
THE PREFABRICATED PINCH BOLT CLAMP AT THE LOWER STEERING SHAFT LOWER YOKE MAY NOT PERFORM ADEQUATELY WHEN TIGHTENED TO SPECIFICATIONS. THE CLAMP MAY THEN DEFORM AND LOSS OF CLAMPING FORCE AND STEERING SHAFT DISENGAGEMENT MAY RESULT.
Remedy
DEALER WILL RETROFIT WITH LOWER STEERING SHAFT LOWER YOKES THAT PROVIDE FOR INTEGRAL PINCH BOLT INSTALLATION IN PLACE OF PREVIOUS SEPARATELY FABRICATED CLAMP FOR THE PINCH BOLT.
The record is thin — 0 NHTSA complaints — so owner-report data can't strongly confirm reliability either way, though 5 recalls should be verified as completed.
Yes — NHTSA lists 5 recall campaigns affecting the 1979 Mack R Series. Recall repairs are free at franchised dealers; check the VIN at nhtsa.gov/recalls to confirm the work was done.
Based on NHTSA ODI data through June 2026. Complaints are consumer-reported and unverified. Updated July 5, 2026.
Compiled by Sharon Ben-Moshe, Founder.